On observation of dispersion in tunable second-order nonlinearities of silicon-rich nitride thin films

TL;DR

This paper reports on the tunable second-order nonlinearities in silicon-rich nitride films, demonstrating significant electric field-induced enhancement and highlighting the dispersive nature of their nonlinear coefficients for potential telecommunication applications.

Contribution

It provides experimental measurements of  in silicon-rich nitride films and explores their tunability via EFISH, revealing their dispersive behavior and implications for integrated photonics.

Findings

 as high as 8 pm/V in as-deposited films

Maximum  of 22.7 pm/V achieved with EFISH

Dispersive nature of  coefficients observed

Abstract

We present experimental results on second-harmonic generation in non-stoichiometric, silicon-rich nitride (SRN) films. The as-deposited film presents a second-order nonlinear coefficient, or \c{hi}(2), as high as 8pm/V. This value can be widely tuned using the electric field induced second harmonic effect (EFISH), and a maximum value of 22.7pm/V was achieved with this technique. We further illustrate that the second-order nonlinear coefficient exhibited by these films can be highly dispersive in nature, and requires further study and analysis to evaluate their viability for in-waveguide applications at telecommunication wavelengths.